In his first-ever interview, the sole Australian survivor of the Waco siege has revealed to 60 Minutes what really took place during the 51-day stand-off, and why he believes crazed cult leader David Koresh will one day return to Earth as the son of God.

WestConnex asbestos claims investigated

Claims that an excavation company has supplied asbestos-contaminated road base, used in Sydney's WestConnex motorway project, is being investigated by the state government.

A former employee of Moits, a Sydney excavation company, claimed the company supplied asbestos-laden road base to the $16.8 billion road project, according to the ABC.

SafeWork NSW confirmed to AAP in a statement on Thursday, it "will continue to look into practices at the recycling plant and will investigate whether WestConnex has received contaminated waste".

Moits disputed the allegations made by the former employee, saying the company "does not and has never recycled products containing asbestos".

"We will never put at risk the safety, health and wellbeing of any employee or the people we supply by playing fast and loose with asbestos," Moits said in a statement on Thursday.

The company said it would continue to cooperate with every regulatory authority, including Safe Work NSW and the EPA to confirm its processes are safe and that the safety and wellbeing of its employees is not being jeopardised.